Sometimes my priviate instance of webpagetest only capturing the last screenshot in filmstrip. is it something to do with my set up ?
Across all browsers? What OS and which version of the test agents? The latest Chrome Canary builds turned on GPU acceleration which could cause what you are seeing (agents fixed and available for an update but not in a full private instance release).
Firefox 21, Chrome 27 - only getting last screenshot sometimes.
IE 8 - i see IE browser getting opened but i don’t see any page gets loaded. and i get “test data missing” always for all URLs
OS version :windows 7 with WPT latest version
if i use the traffic shaping/throttling i am always getting “test data missing always” and i don’t see browser getting opened during the test on test agent.
It sounds like dummynet is not installed. That will cause the “test data missing” issue. By “latest” do you mean what came with 2.11 or did you update to the latest interim release? - https://sites.google.com/a/webpagetest.org/docs/private-instances#TOC-Updating-Test-Agents